package socket;

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;

/**
 * 聊天室服务端
 */
public class Server {
    private ServerSocket serverSocket;
    private List<PrintWriter> allOut = new ArrayList<>();
    public Server(){
        try {
            System.out.println("正在启动服务端");
            serverSocket = new ServerSocket(8090);
            System.out.println("服务端启动完成");
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    public void start(){
        try {
            while (true) {
                System.out.println("等待客户端连接");
                Socket socket = serverSocket.accept();
                System.out.println("一个客户端连接了");
                //启动一个线程处理与客户端交互
                ClientHandler clientHandler = new ClientHandler(socket);
                Thread thread = new Thread(clientHandler);
                thread.start();
            }

        } catch (IOException e) {
            throw new RuntimeException(e);
        }


    }

    public static void main(String[] args) {
        Server server = new Server();
        server.start();
    }
    private class ClientHandler implements Runnable{
        private Socket socket;
        private String host;  //记录客户端的IP地址信息
        public ClientHandler(Socket socket){
            this.socket = socket;
             host = socket.getInetAddress().getHostAddress();
        }
        public void run(){
            PrintWriter pw = null;
            try {
                InputStream is = socket.getInputStream();
                InputStreamReader isr = new InputStreamReader(is, StandardCharsets.UTF_8);
                BufferedReader br = new BufferedReader(isr);

                OutputStream out = socket.getOutputStream();
                OutputStreamWriter osw = new OutputStreamWriter(out,StandardCharsets.UTF_8);
                BufferedWriter bw = new BufferedWriter(osw);
                 pw = new PrintWriter(bw,true);
                 // 将该输出流存入集合allOut中
                 synchronized (allOut){  //锁住集合防止在调用的时候出现并发
                allOut.add(pw);
                 }
                System.out.println("当前在线人数："+allOut.size());

                String line;

                while ((line = br.readLine()) != null) {
                    System.out.println(host +"说" + line  );
                    //将消息回复给所有客户端
                    synchronized (allOut) {
                        for (PrintWriter o : allOut) {
                            o.println(host + "说" + line);
                        }
                    }
                }
            } catch (IOException e) {
                throw new RuntimeException(e);
            }finally {
                synchronized (allOut) {
                    allOut.remove(pw);//将当前客户端输入流从共享集合中删除
                }
                System.out.println(host+"下线了，当前人数："+allOut.size());
                try {
                    socket.close();
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
        }
    }

}
